Polymeric foam scrim sheathings

ABSTRACT

A sheathing adapted to be fastened to at least one wall supporting structure comprises at least two layers. The first layer comprises a polymeric foam layer. The second layer comprises a polymeric scrim and is located adjacent to the first layer. The second layer reinforces its periphery so as to inhibit the failure of the scrim. The reinforced periphery may include a selvage tuck or a folded-edge.

FIELD OF THE INVENTION

The present invention relates generally to sheathings that are used instructures and, more particularly, to polymeric foam sheathing materialsthat are used in prefabricated housing and site built housing.

BACKGROUND OF THE INVENTION

There are different commercial sheathings that are used in theconstruction of buildings. Sheathings include materials that span theframe supports of buildings. Some of the commercial products that havebeen used as sheathing include thin composite laminations, fiberboard,orientated strand board (OSB) and plywood. Some of these productsprovide structural strength, durability and/or rigidity. These products,however, have disadvantages such as being heavy and difficult toinstall, providing little insulation and/or having poor moistureresistance.

There are other commercial products that are available as sheathing. Forexample, polyisocyanurate foam, extruded polystyrene foam, and moldedexpanded polystyrene (EPS) foam. These existing foamed materialsgenerally have advantages such as increased insulation and easierhandling. These existing foamed materials, however, have disadvantagessuch as their lack of strength as measured by wind resistance. This isshown, for example, by their failures to withstand 100 miles per hourwinds when installed behind exterior facing such as siding or brick.Wind resistance may cause problems such as fracturing, cracking and/oredge pull out of the sheathing from the fasteners. During the pulling ofthe edge of the material, the fastener generally remains, but thesheathing is pulled away.

Existing foam sheathing is still susceptible to damage at the buildingsite prior to installation. This problem is further evident when, forexample, delays occur in the installation and/or the installation occursin extreme weather conditions. One common example of damage that mayoccur is when a piece breaks off from a remainder of the sheathingduring the process of installation or by vandalism after installation atthe building site before being covered with an exterior facing such assiding, brick, or stucco.

Accordingly, a need exists for a sheathing that overcomes theabove-noted shortcomings associated with existing sheathing.

SUMMARY OF THE INVENTION

According to one embodiment of the present invention, a sheathingadapted to be fastened to at least one wall supporting structurecomprises at least two layers. The first layer comprises a polymericfoam layer. The second layer comprises a polymeric scrim, and is locatedadjacent to the first layer. The second layer has means for reinforcingits periphery so as to inhibit failure of the sheathing. The reinforcingmeans may include a selvage tuck or a folded-over edge.

According to another embodiment of the present invention, a sheathingadapted to be fastened to at least one wall supporting structurecomprises at least three layers. The first layer comprises a polymericfoam layer, while the second layer comprises a polymeric cross-wovenscrim. The second layer has means for reinforcing its periphery so as toinhibit failure of the sheathing. The third layer comprises an impactpolystyrene and is located between the first and the second layers.

According to one method of the present invention, a sheathing isprovided that comprises at least two layers. The first layer comprises apolymeric foam layer. The second layer comprises a polymeric scrim andis located adjacent to the first layer. The second layer has means forreinforcing its periphery so as to inhibit failure of the sheathing. Thesheathing is installed to a wall supporting structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view of a two-layer sheathing according to oneembodiment of the present invention.

FIG. 2 shows a side view of a three-layer sheathing according to anotherembodiment of the present invention.

FIG. 3 shows a side view of a four-layer sheathing according to anotherembodiment of the present invention.

FIG. 4 shows a side view of a five-layer sheathing according to yetanother embodiment of the present invention.

FIG. 5 shows a side view of a seven-layer sheathing according to afurther embodiment of the present invention.

FIG. 6 shows a cut-away perspective view of a five-layer sheathingfastened to a wall supporting structure according to one embodiment ofthe present invention.

FIG. 7 shows a schematic flow diagram of an overall sequence ofoperations according to one process involved in the manufacture of athree-layer sheathing such as that shown in FIG. 2.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed but, on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by theappended claims.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Turning now to the drawings and referring initially to FIG. 1, atwo-layer sheathing 10 is shown according to one embodiment of thepresent invention. The sheathings of the present invention, includingsheathing 10, are adapted to be fastened to a wall supporting structure.On a building, sheathings are typically covered by an exterior facingsuch as siding, brick or stucco. The sheathing 10 of FIG. 1 comprises apolymeric scrim layer 12 and a polymeric foam layer 14. The polymericscrim layer 12 of the present invention provides additional strength anddurability to the polymeric foam layer 14.

Polymeric Scrim Layer

The polymeric scrim layer 12 may be made of woven material or non-wovenmaterial. Woven material is generally defined as long fibers that areintertwined to produce a material. Non-woven material is generallydefined as randomly joined fibers that are bonded or pressed together byadhesive or other means. The randomly joined fibers that form non-wovenmaterial are typically shorter than those used in forming wovenmaterial. The woven material is generally preferred because it providesan excellent strength to weight ratio that is desirable inwind-resistant applications.

One type of woven scrim that may be used in polymeric scrim layer 12 isa scrim that runs in the machine direction (MD) and the weft ortransverse direction (TD). This is commonly referred to as a cross-wovenscrim. This type of woven scrim may be the type that is commonly used inapplications such as carpet backing. One type of scrim is a 7×4polypropylene scrim. Other scrim counts include 16×5, 10×5 and 12×4. Itis also contemplated that other scrim counts may be used in forming thepolymeric scrim layer of the present invention.

The polymeric scrim layer 12 may be made of materials such aspolyolefins, polyesters and nylons. Polyolefins that may be used in thepolymeric scrim layer 12 include polypropylenes or polyethylenes. Theterm “polypropylene” as used herein includes polymers of propylene orpolymerizing propylene with other aliphatic polyolefins, such asethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene,4-methyl-1-hexene, 5-methyl-1-hexene and mixtures thereof. Polypropylenenot only includes homopolymers of propylene, but also propylenecopolymers comprised of at least 50 mole percent (preferably at least 70mole percent) of a propylene unit and a minor proportion of a monomercopolymerizable with propylene and blends of at least 50 percent byweight of the propylene homopolymer with another polymer.

The term “polyethylene” as used herein includes low density polyethylene(LDPE), medium density polyethylene (MDPE), high density polyethylene(HDPE), very low density polyethylene (VLDPE), linear low densitypolyethylene (LLDPE), metallocene-catalyzed linear low densitypolyethylene (mLLDPE) and combinations thereof.

LDPE is generally defined as an ethylenic polymer having a specificgravity of from about 910 to about 925 kg/m³. MDPE is generally definedas an ethylenic polymer having a specific gravity between the LDPEs andthe HDPEs (i.e., from about 925 to about 940 kg/m³). The high densitypolyethylene (HDPE) of the present invention has a specific gravity offrom about 940 to about 970 kg/m³. The term polyethylene as used hereinincludes homopolymers of ethylene and copolymers comprised of at least50 mole percent of a ethylene unit (preferably at least 70 mole percent)and a minor (i.e., less than 50%) proportion of a monomercopolymerizable with the ethylene unit. The term LDPE as used hereinalso includes physical blends of two or more different homopolymers thatare classified as LDPEs. Similarly, the term MDPE and HDPE may alsoinclude blends of two or more different homopolymers classified as MDPEsand HDPEs, respectively.

The VLDPE resins have densities ranging from about 880 to about 912kg/m³, more commonly from about 890 to about 910 kg/m³, and melt indicesof from about 0.5 to about 5 g/10 min., and from about 1 to about 3 g/10min.

The LLDPE of the present invention generally has from about 1 to about20, preferably from about 1 to about 10 weight percent of said higheralpha olefin monomer copolymerized therein. In addition, the alphaolefin monomer employed in the ethylenic copolymer may be selected fromthe group consisting of 1-butene, 3-methyl-1-butene, 3-methyl-1-pentene,1-hexene, 4-methyl-1-pentene, 3-methyl-1-hexene, 1-octene and 1-decene.The LLDPE resins that may be used in the present invention havedensities ranging from about 890 to about 940 kg/M³, more commonly fromabout 900 to about 930 kg/m³, and a melt index (I₂) of from about 1 toabout 10 g/10 min. as determined by ASTM D)1238.

The metallocene-catalyzed polyethylene (mLLDPE) is a polymer having alow polydispersity. The low polydispersity polymer may be prepared froma partially crystalline polyethylene resin that is a polymer preparedwith ethylene and at least one alpha olefin monomer, e.g., a copolymeror terpolymer. The alpha olefin monomer generally has from about 3 toabout 12 carbon atoms, preferably from about 4 to about 10 carbon atoms,and more preferably from about 6 to about 8 carbon atoms. The alphaolefin comonomer content is generally below about 30 weight percent,preferably below about 20 weight percent, and more preferably from about1 to about 15 weight percent. Exemplary comonomers include propylene,1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene,1-octene, 1-decene, and 1-dodecene.

The low polydispersity polymer has a density of from about 880 to about940 kg/m³. The polydispersity polymer should have a molecular weightdistribution, or polydispersity, (M_(w)/M_(n), “MWD”) within the rangeof from about 1 to about 4, and more typically from about 2 to about 3.The melt flow ratio (MFR) of these polymers, defined as I₂₀/I₂ and asdetermined in accordance to ASTM D1238, is generally from about 12 toabout 22 and typically from about 14 to about 20. The melt index (MI),defined as the I₂ value, should be in the range of from about 0.5 toabout 10 g/10 min. and typically from about 1 to about 5 g/10 min. asdetermined by ASTM D1238.

An example of a “polyester” includes a polyester resin which is apolycondensation product of a dicarboxylic acid with a dihydroxyalcohol. An example of a “polyethylene terephthalate” includes apolyester resin made from ethylene glycol and terephthalic acid. Anexample of a “nylon” is a polyamide polymer that is characterized by thepresence of the amide group (—CONH).

The polymeric scrim layer 12 has means for reinforcing its periphery soas to inhibit the failure of the sheathing. The polymeric scrim layermay have a reinforced periphery via a selvage tuck or a folded-overedge.

Selvage tucking is generally defined as weaving or laminating theperiphery of the sheathing so as to inhibit failure of the sheathing.One example of the sheathing failing is when the periphery of thesheathing is pulled out from the fastener attaching the sheathing to awall supporting structure (see, e.g., wall supporting structure 22 ofFIG. 6). One type of selvage type that can be used is a lenolatchselvage tuck. The lenolatch selvage tuck incorporates a lenolatch cordthat locks fill yarns so as to prevent or inhibit the scrim fromunraveling. The selvage tuck is preferably located on at least twoopposing portions of the periphery of the polymeric scrim layer. It ispreferred that the selvage tuck extends along two entire sides of thepolymeric scrim layer. More specifically, the selvage tuck is preferablylocated near two opposing edge portions. It is contemplated that theselvage tuck may be located on all sides of the polymeric scrim layer.

It is contemplated that additional polymeric scrim layer(s) can be addedto the sheathing. For example, the sheathing may include polymeric scrimlayers on opposing sides of the polymeric foam layer.

Polymeric Foam Layer

The polymeric foam layer 14 is located adjacent to the scrim layer 12 inFIG. 1. The polymeric foam layer 14 may be made from alkenyl aromaticresins, such as polystyrenic resin(s), and polyesters such aspolyethylene terephthalates. The term “alkenyl aromatic polymer” as usedherein includes polymers of aromatic hydrocarbon molecules that containan aryl group joined to an olefinic group with only double bonds in thelinear structure. The polymeric foam layer 14 may also be made frompolyolefinic resins such as LDPEs, HDPEs, LLDPEs, and the like. Thepolymeric foam layer 14 is preferably made from a polystyrenic resin(s),such as a general purpose polystyrene, because of economicalconsiderations at the present time. The polymeric foam layer 14,however, may be made from other polystyrenic resins such as impactpolystyrenes. The impact polystyrenes that are generally used includemedium impact polystyrenes and high impact polystyrenes. The polymericfoam layer 14 may also be made from a combination of virgin and/orreprocessed material.

The polymeric foam layer 14 and the polymeric scrim layer 12 may bebonded by attaching, adhering, fusing or the like. For example, thepolymeric foam layer 14 and the polymeric scrim layer 12 may bethermally bonded to each another depending on the selected materials forforming the layers 12 and 14. Thermal bonding may be accomplished byconventional methods, such as a flameless air torches, heated rolls,radiant heaters and infrared heating.

Adhesive and Other Layers

Alternatively, the polymeric foam layer 14 and the polymeric scrim layer12 may be attached with an adhesive layer. This is shown in FIG. 2 wheresheathing 30 includes a polymeric scrim layer 12, a polymeric foam layer14 and an adhesive layer 16. The optional adhesive layer 16 is locatedbetween the polymeric scrim layer 12 and the polymeric foam layer 14.One type of adhesive that may be used is ethylene vinyl acetate (EVA).For example, modified EVAs such as BYNEL® made by DuPONT® or Plexar®made by Equistar Chemicals may be used. These modified EVAs have meltindices generally from about 6.4 to about 25 g/10 min. as measured byASTM D1238 and densities generally from about 0.923 to about 0.947 g/cm³as measured by ASTM D1505. BYNEL® is an adhesive that is designed tobond materials that would not ordinarily adhere to each other.

Other adhesives that may be used include block copolymers that comprisepolymeric regions of styrene-rubber-styrene. For example, KRATON® madeby Shell® Chemical Company may be used. Other adhesives are contemplatedin the present invention to bond the polymeric scrim layer 12 to thepolymeric foam layer 14.

Additional layers are contemplated in the sheathings of the presentinvention. For example, FIGS. 3, 4 and 5 depict a four-layer sheathing,a five-layer sheathing and a seven-layer sheathing, respectively.Referring specifically to FIG. 3, sheathing 40 includes a polymericscrim layer 12, a polymeric foam layer 14, an adhesive layer 16 and animpact polystyrenic layer 18. The polystyrenic layer 18 is preferablymade from a high impact polystyrene because of its desired stiffness.The polystyrenic layer 18 may be biaxially orientated so as to provideadditional durability and flexibility.

FIG. 4 depicts a sheathing 50 that is similar to the sheathing 40 ofFIG. 3, except that the sheathing 50 includes an additional impactpolystyrenic layer 18. Sheathing 60 of FIG. 5 comprises the same fivelayers of the sheathing 50 of FIG. 4. The sheathing 60 of FIG. 5,however, also comprises two additional layers. Specifically, thesheathing 60 includes an additional adhesive layer 16 and a polymericfilm layer 20. To provide additional strength and durability, thepolymeric film layer 20 may be made from a polyolefin(s) such aspolypropylene.

Other layers are contemplated for the sheathings of the presentinvention. For example, the sheathings of the present invention mayinclude radiant barrier layers or flame retardant layers.

Properties of the Sheathing

The sheathings of the present invention generally have a flexuralstrength of at least 125 lbs./in.², preferably at least 175 lbs./in.²and most preferably at least 200 lbs./in.² as measured by ASTM D1307.The sheathings of the present invention have excellent strength so as toprovide resistance to high winds. The sheathings of the presentinvention preferably satisfy the structural design requirements as setforth in the H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) for Wind Zone II conditions (a designwind speed of 100 miles per hour) taken from §3280.305(c) of the FederalRegister. The sheathings also preferably satisfy the structural designrequirements as set forth in H.U.D. Guide for Manufactured HomeStandards Programs (9^(th) edition, December 1994) for Wind Zone IIIconditions (a design wind speed of 110 mph) taken from §3280.305(c) ofthe Federal Register.

The sheathings of the present invention may be formed into a number ofshapes. For example, the sheathing may be a flat sheet or a folded orhinged board (typically referred to as a fanfolded sheathing). Thefanfold sheathing is designed to unfold at its hinges and includes anumber of individual panels.

The sheathings of the present invention may be manufactured in a varietyof sizes. Popular sizes used in the housing market include a 4 foot by 7foot (4′×7′), 4′33 7½′, 4′×8′ and 4′×9′ flat sheets. Other popular sizein the housing market include a 4′×50′ fanfolded sheathing whichincludes a number of individual panels. If a fanfolded sheathing isused, it is preferred to have cross-members in the wall supportingstructure for which the fanfolded sheathing may be attached.

The thickness of the sheathings may also vary, but is generally fromabout ⅛ of an inch to about 2 inches as measured by ASTM D1622-88. Thethickness of the sheathing is typically from about ¼ of an inch to about1 inch. Popular thicknesses of the sheathing include about ¼, about5/16, about ⅜, about ½ and about ¾ of an inch.

The layers of the sheathings typically vary in their respective weightpercent relative to each other. The sheathings generally comprise fromabout 2 wt. % to about 30 wt. % of the polymeric scrim layer(s) 12. Thesheathings generally comprise from about 25 wt. % to about 99 wt. % ofthe polymeric foam layer(s) 14. The sheathings generally comprise from 0wt. % to about 15 wt. % of the adhesive layer(s) 16. It is contemplatedthat the remainder of the sheathings may include other optional layers.The sheathings generally comprise from 0 wt. % to about 50 wt. % of theimpact polystyrenic layer(s) 18 and from 0 wt. % to about 50 wt. % ofthe polymeric film layer(s) 20.

The sheathings preferably comprise from about 2 to about 25 wt. %, andmost preferably from about 4 wt. % to about 20 wt. % of the polymericscrim layer(s) 12. The sheathings preferably comprise from about 30 toabout 95 wt. %, and most preferably from about 40 wt. % to about 90 wt.% of the polymeric foam layer(s) 14. Preferably, the sheathings comprisefrom about 1 to about 10 wt. %, and most preferably from about 1 wt. %to about 7 wt. % of the adhesive layer(s) 16. The sheathings preferablycomprise from about 5 to about 35 wt. %, and most preferably from about5 wt. % to about 30 wt. % of the impact polystyrenic layer(s) 18. Thesheathings preferably comprise from 0 to about 25 wt. %, and mostpreferably from 0 wt. % to about 20 wt. % of the polymeric film layer(s)20.

The sheathings of the present invention may be used in various buildingssuch as prefabricated housing (also referred to as manufactured housing)and site built housing. The sheathing may be installed to a wallsupporting structure. One example is shown in FIG. 6 where a sheathing52 is installed to a plurality of wall supporting structures 22. Thesheathing 52 a has been cut-away to depict the various layers 12, 14, 16and 18, while sheathing 52 b has not been cut-away in FIG. 6. FIG. 6also shows siding 56 being located on an exterior surface of thesheathing 52.

The sheathing 52 of FIG. 6 may be installed to the plurality of wallsupporting structure 22 by the use of fasteners (not shown). Thefastener may be a mechanical fastener such as a staple or nail. Thesheathing 52 preferably has at least two opposing reinforced portions ofits peripheries (e.g., selvage tuck). Two opposing reinforced portionsextend along entire opposing sides and are approximately parallel to oneof the plurality of wall supporting structures 22. The opposingreinforced peripheries 54 are located on the vertical sides of thesheathing 52 in FIG. 6. The general location of one of the opposingreinforced portions 54 b is shown on sheathing 52 b in FIG. 6, while theother opposing reinforced portion has been cut-away in sheathing 52 band, thus, is not shown in FIG. 6. Likewise, only one of the opposingreinforced portions 54 a is shown on sheathing 52 a.

It is contemplated that the sheathing of the present invention may beused in a roofing application to provide additional strength, to resistwind uplift and to provide durability that minimizes breakage duringhandling and installation. The sheathing may be used as an underlaymentfor low slope roofs.

PROCESS OF THE PRESENT INVENTION

According to one process of the present invention, a polymeric web offoam is provided to form the polymeric foam layer. The process may use asingle twin screw extruder or a tandem foam extrusion line. For example,the process begins by loading pellets of a polymeric resin(s) such aspolystyrenic foam resin. The polymeric resins in their solid form areadded into an extrusion hopper.

A nucleating agent (also referred to as cell size control agent) orcombination of such nucleating agents may be employed in the process ofthe present invention for advantages such as their capability forregulating cell formation and morphology. The amount of nucleating agentto be added depends upon the desired cell size, the selected blowingagent and the density of the polymeric composition. Known nucleatingagents such as talc, mixtures of sodium bicarbonate and citric acid, andthe like may be employed in the present invention.

It is contemplated that stability control agent(s) may also be added tothe polymeric resin(s), including conventional stability control agents.Some examples of stability control agents that may be used include, butare not limited to, glycerol monostearate, saturated higher fatty acidamides and glycerol monoester of a C₂₀-C₂₄ fatty acid.

If desired, fillers, colorants, light and heat stabilizers,plasticizers, chemical blowing agents, flame retardants, foamingadditives and plastic compounding agents may be added to the polymericcomposition. The polymeric composition comprises the polymeric resinand, if added, the nucleating agent, the stability control agent andadditives. The polymeric composition is conveyed through a feed zone ofthe extruder and heated at a temperature sufficient to form a polymericmelt.

A physical blowing agent may be added at the injection port area of theextruder in an appropriate ratio to the target density. The selectedblowing agent may be any type that is capable of producing foam with theselected resin. Some examples of blowing agents include physical blowingagents such as halocarbons, hydrocarbons or combinations thereof.Examples of these include commercially available hydrofluorocarbons,such as HFC-152a and HFC-134a, hydrochlorofluorocarbons, such as HCFC-22or HCFC-142b, and the C₃-C₆ hydrocarbons. Other types of blowing agentsinclude carbon dioxide. The polymeric composition and the selectedblowing agent are thoroughly mixed within the extruder in a mixing zoneand subsequently cooled in a cooling zone. The cooled polymeric-blowingagent melt is extruded thorough a die.

One method of the present invention for making a three-layer sheathingis shown in a schematic flow diagram in FIG. 7. In the process of FIG.7, the polymeric foam is extruded from an extruder 70 through a rounddie 72. After exiting the round die 72, the extrudate expands whenentering a lower pressure region (e.g., the atmosphere) and forms apolymeric web of foam. The polymeric web of foam is stretched over asizing mandrel 74 to size and then is slit to form the web of foam. Thepolymeric web of foam will eventually be used in forming the polymericfoam layer 14.

At least one of the outer surfaces of the polymeric web of foam istypically cooled so as to form a “skin.” The skin is typically about afew thousands (or a few mils) thick, but may vary depending on thecooling employed. The skin provides additional strength and alsoprovides a smoother surface that is more aesthetically pleasing to aconsumer if the polymeric layer is visible to the customer. It iscontemplated that cooling methods may be accomplished by using air andwater. The skinning may be performed, for example, by stretching thepolymeric foam of web 76 over the sizing mandrel 74 with optionalcooling wherein either surface of the polymeric foam of web 76 iscooled. It is contemplated that one or more of the surfaces of thepolymeric web of foam may be cooled.

The polymeric foam web 76 proceeds to travel around a S-wrap of rollers78 a-c in which roller 78 a is an idler roller and rollers 78 b and 78 care driven or pull rollers. The driven rollers 78 b, 78 c assist inmoving the polymeric foam web 76 through the process of the presentinvention. The polymeric foam web 76 proceeds between two driven rollers80 a,b. Driven rollers 80 a,b assist in maintaining a consistent surfaceon which a web of adhesive 82 a is added via an adhesive coating or alaminating machine 82. The adhesive machine 82 may be any conventionalmachine that is capable of applying the adhesive web 82 a to thepolymeric foam web 76. The adhesive machine 82 may coextrude the web ofadhesive 82 a with a second web, such as a web of impact polystyrene(not shown).

At the about the same time, a web of scrim 84 a is added via a rollunwind cart system 84. The cart system 84 may include an edge alignmentsystem to properly align the web of scrim 84 a to the polymeric foam web76. After exiting the driven rollers 80 a,b, the polymeric foam web 76,the web of adhesive 82 a and the web of scrim 84 a form a sheathing web86.

It is contemplated that the sheathing web 86 may be processed to includeprinting on one or more surfaces or other treatments. The process ofFIG. 7 includes an optional printer 88 that prints on one surface of thesheathing web 86. It is contemplated that the printing may occur on thepolymeric foam web 76 before the webs of adhesive and scrim are added tothe polymeric foam web 76. The sheathing web 86 proceeds around a seriesof rollers 90 a-90d and then to an optional edge trim system 92. Theedge trim system assists in sizing the sheathing web 86 to be used informing the sheathing of the present invention.

As shown in FIG. 7, the sheathing web 86 proceeds through an optionalperforating creasing machine 94. The perforating creasing equipment 94may include any conventional equipment that is capable of folding thesheathing web 86 of the present invention into a fanfold sheathing web.Of course, if flat sheathing is desired, the creasing equipment 94should not be included in the process. A perforating machine, however,may be used in producing a flat sheathing. The sheathing web is then cutto a desired dimension by shearing equipment 96. The shearing equipment96 may be any equipment capable of cutting the sheathing web 86 intodesired dimensions. It is also contemplated that other finishingoperations may occur such as stacking, counting, packaging and trimming.It is also contemplated that various measurements may be takenthroughout the process to ensure consistent measurements.

According to a second process of the present invention (not shown),additional layers may be added in forming other sheathings, such asthose described above. For example, a machine (not shown) may be addedto the process of FIG. 7 that is adapted to add an additional impactpolystyrenic web to the polymeric web of foam.

EXAMPLES Example 1

Negative wind pressure load tests were conducted on samples of sheathing(“Sheathing 1”) using a 2×4 (1½ inches×3½ inches) stud as a wallsupporting structure. Sheathing 1 had dimensions of 48 inches by 90inches (48″×90″). Sheathing 1 consisted of five layers with the firstlayer being a woven polypropylene scrim with a selvage tack. The secondlayer was made of a BYNEL® adhesive. The third and fifth layers weremade of high impact polystyrene. The second layer was located betweenthe first and third layers. The fourth layer was a polystyrene foam andwas located between the third and fifth layers. This is a similarstructure as shown above in FIG. 4. The following describes the testspecimens that were used in Example 1.

Example 1 Specimen Description

A. Materials

-   -   1. Stud: 2×4, Stud Grade spruce pine fur (SPF) spaced at 16″ on        center (o.c.)    -   2. Top Plate: Single 1×4, Ungraded SPF    -   3. Bottom Plate: Single 1×4, Ungraded SPF    -   4. Gypsum: 5/16″ U.S. Gypsum, 5/16″ National Gypsum or 5/16″        Georgia Pacific    -   5. Siding: Georgia Pacific Parkside® D5 Vinyl Siding with a        nailing flange thickness of 0.038 inch.

B. Fastening

-   -   Top plate attached to studs with three (3)— 7/16×1¾″×16 gauge        (Ga.) Staples.    -   Bottom plate attached to studs with three (3)— 7/16″×1¾″×16 Ga.        Staples.    -   Sheathing 1 fastened with 1″×1½″×16 Ga. staples at 3″ o.c.        around perimeter and 3″ o.c. in the field.    -   In Zone II test samples, staples are 3″ o.c. in both center        studs.    -   Gypsum fastened to frame with ¼″×1″×19 Ga. staples at 6″ o.c.        around perimeter and no field fasteners.    -   Gypsum glued to frame with a ⅜″ bead of PVA glue on all framing        members.    -   Siding fastened to sheathing into the studs with 7/16″×1½″×16        Ga. staples at 16″ o.c. per strip of siding.

C. Construction

The 48″×90″ test sample was first assembled with 2×4 studs that were88.5 inches long. The top and bottom plates were 49.5 inches long.Polyethylene sheeting (6 mil) was placed between the 2×4 framing andSheathing 1. The framing was then squared with Sheathing 1 and fastenedas described above. The horizontal vinyl siding was fastened throughSheathing 1 into the studs. The 5/16″ gypsum was then fastened to theopposite side of the frame as described above. Glue was allowed to curefor 7 days before the testing began. Materials for the assemblies testedwere commercially purchased products.

Example 1 Test Setup and Procedure

The testing was conducted in accordance with the ultimate load testprocedures in H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) taken from §3280.401(b) of the FederalRegister. An 11-¼″ deep wood box was built 1″ wider and 1″ longer thanthe test sample. The top and bottom plates of the test samples weresecured to 2×4 ledgers. The test samples were placed horizontally on thetest fixture with the vinyl siding facing down, and the ledgers bearingon top of the wood box. The polyethylene sheeting (6 mil) that wasplaced between the wall framing and Sheathing 1 was sealed to the table.This allowed the entire surface of Sheathing 1 to be exposed to the fullnegative loads.

The uniform load was applied by evacuating the air below the testspecimen using a vacuum pump. The applied load was measured with a watermanometer capable of reading in 0.1 inch increments. The load wasapplied in approximate ¼ design live load increments at 10 minuteintervals until 1.25 times design load was reached. The load was thenincreased to 2.5 times design load or until failure occurred. The loadin inches of water column was converted to pounds per square foot (psf)by using the conversion of 1 inch (of water column) to 5.2 psf.

Deflections were taken using dial indicators capable of reading in0.001″ increments. The deflections were taken at the quarter-points ofthe center stud.

Example 1 Results

A total of three specimens were tested for each specific gypsum ( 5/16″U.S. Gypsum, 5/16″ National Gypsum or 5/16″ Georgia Pacific) fornon-corner and corner Wind Zone II requirements. The product sold byU.S. Gypsum Company that was used was 5/16″ Manufactured Housing GypsumBaseboard. The product sold by National Gypsum Company that was used was5/16″ Gold Bond® Gypsum Wallboard. The product sold by Georgia PacificCorporation that was used was 5/16″ PreDeck® Gypsum Board. Experiments 1and 2 used U.S Gypsum, Experiments 3 and 4 used National Gypsum, whileExperiments 5 and 6 used Georgia Pacific. The ultimate load in poundsper square foot (psf) was determined in accordance with H.U.D. Guide forManufactured Home Standards Programs (9^(th) edition, December 1994)taken from §3280.401(b) of the Federal Register. The ultimate load wastaken for three specimens (S1, S2 and S3). The average of these threespecimens is shown under the “AVG.” column. The results are as followsin Table 1. TABLE 1 EXPER. ULTIMATE LOAD (PSF) AVG. DEFLECTION NO. S1 S2S3 (PSF) (PASS/FAIL) WIND ZONE 1 96.72 96.72 95.68 96.37 PASSED IINon-Corner 2 120.64 121.68 122.72 121.68 PASSED II Corner 3 95.68 96.7297.76 96.72 PASSED II Non-Corner 4 121.68 122.72 120.64 121.68 PASSED IICorner 5 95.68 98.8 97.76 97.41 PASSED II Non-Corner 6 120.64 121.68124.8 122.37 PASSED II Corner

Each of the gypsums at the non-corner and corner conditions inExperiments 1-6 passed the deflection test for Wind Zone II. Inaddition, each of the gypsums at the non-corner and corner conditions inExperiments 1-6 satisfied the ultimate load for Wind Zone II. Theultimate load requirement for Wind Zone II for a non-corner condition is95 psf, while the ultimate load requirement for Wind Zone II for acorner condition is 120 psf.

Example 2

Negative wind pressure load tests were conducted on samples of 48″×90″Sheathing 1 (described above in Example 1) without a selvage tuck on thescrim layer using a 2×4 stud as a wall supporting structure. Thefollowing describes the test specimens that were used in Example 2.

Example 2 Specimen Description

A. Materials

-   -   1. Stud: 2×4, Stud Grade SPF spaced at 16″ (o.c.)    -   2. Top Plate: Single 1×4, Ungraded SPF    -   3. Bottom Plate: Single 1×4, Ungraded SPF    -   4. Gypsum: 5/16″ U.S. Gypsum    -   5. Siding: Georgia Pacific Parkside® D5 Vinyl Siding with a        nailing flange thickness of 0.038 inch.

B. Fastening

-   -   Top plate attached to studs with five (5)— 7/16″×1¾″×16 Ga.        Staples.    -   Bottom plate attached to studs with five (5)— 7/16″×1¾″×16 Ga.        Staples.    -   Sheathing 1 fastened with 1″×1½″×16 Ga. staples at 3″ o.c.        around perimeter and 3″ o.c. in the field.    -   Gypsum glued to frame with a ⅜″ bead of PVA glue on all framing        members.    -   Siding fastened to sheathing into the studs with 7/16″×1½″×16        Ga. staples at 16″ o.c. per strip of siding.

C. Construction

The construction similar to that described above in Example 1.

Example 2 Test Setup and Procedure

The test setup and procedure were similar to that described above inExample 1.

Example 2 Results

One specimen (S1) was tested using 5/16″ U.S. Gypsum for non-corner WindZone III. The results are as follows in Table 2. TABLE 2 EXPER. ULTIMATELOAD (PSF) AVG DEFLECTION NO. S1 S2 S3 (PSF) (PASS/FAIL) WIND ZONE 799.84 N/A PASSING III Non-Comer

Experiment 7 did not pass the requirement for ultimate load under WindZone III using 2×4 studs. Experiment 7 was not completed because thesheathing pulled over the staples. At the time when Experiment 7 wasstopped, specimen S1 was passing the deflection test for Wind Zone III.It is believed, however, that if Experiment 7 had continued, thenspecimen S1 likely would have not passed the deflection test for WindZone III.

Example 3

Negative wind pressure load tests were conducted on samples of 48″×90″Sheathing 1 (described above in Example 1) without a selvage tuck on thescrim layer using a 2×6 stud as a wall supporting structure. Thefollowing describes the test specimens that were used in Example 3.

Example 3 Test Specimen Description

A. Materials

-   -   1. Wall Stud: 2×6, Stud Grade SPF spaced at 16″ (o.c.)    -   2. Top Plate: Single 1×6, Ungraded SPF    -   3. Bottom Plate: Single 1×6, Ungraded SPF    -   4. Siding: Georgia Pacific Parkside® D5 Vinyl Siding with a        nailing flange thickness of 0.038 inch.

B. Fastening

-   -   Top plate attached to studs with five (5)— 7/16″×1¾″×16 Ga.        Staples.    -   Bottom plate attached to studs with five (5)— 7/16″×1¾″×16 Ga.        Staples.    -   Adhesive—Not used    -   Gypsum—Not used    -   Sheathing 1 fastened with 1″×1¼″×16 Ga. Staples, Angled at 45        degrees at 3″ o.c. in the field and 3″ o.c. around perimeter.    -   Siding fastened to sheathing into the studs with 7/16″×1½″×16        Ga. Staples at 16″ o.c. per strip of siding.

Construction

The construction similar to Example 1 except the studs in Example 3 were2×6. TABLE 3 EXPER. ULTIMATE LOAD (PSF) AVG DEFLECTION NO. S1 S2 S3(PSF) (PASS/FAIL) WIND ZONE 8 171.6 N/A PASSED III Corner

Experiment 8 passed the requirement for ultimate load under a cornercondition for Wind Zone III using 2×6 studs. Experiment 8 also passedthe requirement for deflection under a corner condition for Wind ZoneIII using 2×6 studs.

Example 4

Two specimens of Sheathing 1 were tested for surface burning inaccordance with the procedure set forth in ASTM E 84/UL 723 (Test ForSurface Burning Characteristics of Building Materials). The firstspecimen had a flame spread rating of 0 and a smoke developed rating of20. The second specimen had a flame spread rating of 0 and a smokedeveloped rating of 75.

Sheathing 1 complied with H.U.D. Guide for Manufactured Home StandardsPrograms (9^(th) edition, December 1994) taken from Section3280.207(a)2.i of the Federal Register with respect to the flame spreadrating because the flame spread rating was 75 or less. Sheathing 1 alsocomplied with H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) taken from Section 3280.207(a)2.i of theFederal Register with respect to the smoke developed rating because thesmoke developed rating was 450 or less.

While the present invention has been described with reference to one ormore particular embodiments, those skilled in the art will recognizethat many changes may be made thereto without departing from the spiritand scope of the present invention. Each of these embodiments andobvious variations thereof is contemplated as falling within the spiritand scope of the claimed invention, which is set forth in the followingclaims.

1-41. (canceled)
 42. A sheathing adapted to be fastened to at least onewall supporting structure, comprising: (a) a first layer comprising apolymeric foam layer; (b) a second layer comprising a polymeric scrim,said second layer having means for reinforcing its periphery so as toinhibit failure of the scrim; (c) an adhesive; (d) a third layercomprising an impact polystyrene, said adhesive being located betweensaid second layer and said third layer, said third layer being locatedbetween said first layer and said adhesive.
 43. The sheathing of claim42, wherein the means for reinforcing is a folded-over edge.
 44. Thesheathing of claim 42, wherein the means for reinforcing is a selvagetuck.
 45. The sheathing of claim 44, wherein said selvage tuck islocated on at least two opposing portions of the periphery of saidsecond layer.
 46. The sheathing of claim 42, wherein said first layer isa polyolefin foam.
 47. The sheathing of claim 42 further comprising afourth layer comprising an impact polystyrene, said first layer beinglocated between said third layer and said fourth layer.
 48. Thesheathing of claim 42, wherein said first layer is a polystyrenic foam.49. The sheathing of claim 42, wherein said polymeric scrim is apolyolefinic scrim.
 50. The sheathing of claim 49, wherein saidpolyolefinic scrim is made from polyolefins, said polyolefinic scrimbeing made of polypropylene, polyethylene or a combination thereof. 51.The sheathing of claim 42, wherein said polymeric scrim ispolypropylene.
 52. The sheathing of claim 42, wherein said polymericscrim is polypropylene and said first layer is a polystyrenic foam. 53.The sheathing of claim 42 wherein said sheathing is classified as a WindZone II material in accordance with H.U.D. Guide for Manufactured HomeStandards Programs (9th edition, December 1994) taken from §3280.401(b)of the Federal Register.
 54. The sheathing of claim 42 wherein saidsheathing is classified as a Wind Zone III material in accordance withH.U.D. Guide for Manufactured Home Standards Programs (9th edition,December 1994) taken from §3280.401(b) of the Federal Register.
 55. Thesheathing of claim 42, wherein said second layer is a woven polymericscrim.
 56. The sheathing of claim 42, wherein said second layer is across-woven polymeric scrim.
 57. A sheathing adapted to be fastened toat least one wall supporting structure, comprising at least threelayers: (a) a first layer comprising a polymeric foam layer; (b) asecond layer comprising a polymeric cross-woven scrim, said second layerhaving means for reinforcing its periphery so as to inhibit failure ofthe scrim; and (c) a third layer comprising an impact polystyrene, saidthird layer being located between said first and said second layers. 58.The sheathing of claim 57 further including a fourth layer comprising animpact polystyrene, said fourth layer being located adjacent to saidfirst layer and said first layer being located between said third andsaid fourth layers.
 59. The sheathing of claim 58 further including anadhesive being located between said second and third layers.
 60. Thesheathing of claim 57 further including an adhesive, said adhesive beinglocated between said second and third layers.
 61. The sheathing of claim57, wherein said polymeric foam is a polyolefin foam.
 62. The sheathingof claim 57, wherein said polymeric foam is a polystyrenic foam.
 63. Thesheathing of claim 57, wherein said woven scrim is a woven polypropylenescrim.
 64. The sheathing of claim 57, wherein said means for reinforcingis a selvage tuck.
 65. The sheathing of claim 57, wherein said polymericfoam is polystyrenic foam, said polymeric scrim is a woven polypropylenescrim and wherein said sheathing further includes a fourth layer and anadhesive, said fourth layer comprising an impact polystyrene and islocated adjacent to said first layer, said first layer is locatedbetween said third and said fourth layers and said adhesive is locatedbetween said second and third layers.
 66. The sheathing of claim 57,wherein the sheathing has a thickness of from about 0.25 inch to about1.0 inch.
 67. The sheathing of claim 57, wherein said means forreinforcing is a folded-over edge.
 68. The sheathing of claim 57,wherein said woven scrim is a woven polyolefin scrim.